const canvas = c => {
	var ctx = c.getContext("2d")
	var w = c.width = window.innerWidth;
	var h = c.height = window.innerHeight;
	var clearColor = 'rgba(0, 0, 0, .1)';
	var max = 30;
	var drops = [];

	function random(min, max) {
	    return Math.random() * (max - min) + min;
	}

	function O() {}

	O.prototype = {
		init: function() {
			this.x = random(0, w);
			this.y = 0;
			this.color = 'hsl(180, 100%, 50%)';
			this.w = 2;
			this.h = 1;
			this.vy = random(4, 5);
			this.vw = 3;
			this.vh = 1;
			this.size = 2;
			this.hit = random(h * .8, h * .9);
			this.a = 1;
			this.va = .96;
		},
		draw: function() {
			if (this.y > this.hit) {
				ctx.beginPath();
				ctx.moveTo(this.x, this.y - this.h / 2);

				ctx.bezierCurveTo(
					this.x + this.w / 2, this.y - this.h / 2,
					this.x + this.w / 2, this.y + this.h / 2,
					this.x, this.y + this.h / 2);

				ctx.bezierCurveTo(
					this.x - this.w / 2, this.y + this.h / 2,
					this.x - this.w / 2, this.y - this.h / 2,
					this.x, this.y - this.h / 2);

				ctx.strokeStyle = 'hsla(180, 100%, 50%, '+this.a+')';
				ctx.stroke();
				ctx.closePath();
				
			} else {
				ctx.fillStyle = this.color;
				ctx.fillRect(this.x, this.y, this.size, this.size * 5);
			}
			this.update();
		},
		update: function() {
			if(this.y < this.hit){
				this.y += this.vy;
			} else {
				if(this.a > .03){
					this.w += this.vw;
					this.h += this.vh;
					if(this.w > 100){
						this.a *= this.va;
						this.vw *= .98;
						this.vh *= .98;
					}
				} else {
					this.init();
				}
			}
			
		}
	}

	function resize(){
		w = c.width = window.innerWidth;
		h = c.height = window.innerHeight;
	}

	function setup(){
		for(var i = 0; i < max; i++){
			(function(j){
				setTimeout(function(){
					var o = new O();
					o.init();
					drops.push(o);
				}, j * 200)
			}(i));
		}
	}


	function anim() {
		ctx.fillStyle = clearColor;
		ctx.fillRect(0,0,w,h);
		for(var i in drops){
			drops[i].draw();
		}
		requestAnimationFrame(anim);
	}


	window.addEventListener("resize", resize);

	setup();
	anim();

}

export default canvas